Yes you can do this!
You should probably use your same Author Name / Pen Name you use for a book accross all sites though. The only reason we say that is, Amazon may search your cover and see it somewhere else, with the same or simular title and may think you are copying it. This may not happen, just being upfront about it and what might happen, no matter how small a chance.
One thing though, if you have a medium content book on Amazon and they gave you a free ISBN, do not use their ISBN at other sites.
If you have purchased your own, then you can use everywhere.